<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <script src="jquery.js" charset="utf-8"></script>
    <script>
    Promise.all([
      $.ajax({url: '1.txt', dataType: 'json'}),
      $.ajax({url: '2.txt', dataType: 'json'}),
      $.ajax({url: '3.txt', dataType: 'json'}),
    ]).then(arr=>{
      let [j1, a, j2]=arr;

      console.log(j1, a, j2);
    }, err=>{
      alert('失败');
    });
    </script>
  </head>
  <body>

  </body>
</html>
